ibclogo XVI International Botanical Congess


Abstract Number: 5567
Poster No. = 728


CHALLENGING THE BETALAIN DOGMA: STUDIES ON THE PHYLOGENETIC POSITION OF THE MOLLUGINACEAE (CARYOPHYLLALES)


Robert S. Wallace, Iowa State University, Ames, Iowa 50011-1020 USA


The well-known situation of mutual exclusivity of betalain and anthocyanin pigments in the Caryophyllales delimits the two anthocyanic families Caryophyllaceae and Molluginaceae as distinct from the other betalain-producing families. Previous studies using a wide variety of data have failed to demonstrate a sister-group relationship for these two familes. Historically, the Molluginaceae had been associated with the Aizoaceae, and based upon select anatomical, cytological, and embryological evidence, could be readily placed within or adjacent to the Aizoaceae, were it not for the derived condition of betalain production in the Aizoaceae. To include the Molluginaceae with the Aizoaceae would therefore require the loss of betalain production and a reversion to anthocyanin production in the former group. To investigate this scenario, DNA sequence data are used to examine the phylogenetic affinities of the Molluginaceae, and to examine a relationship, if any, to the Aizoaceae, or other families of the Phytolaccaceous alliance.


HTML-Version made 7. July 1999 by Kurt Stüber